This application requests support for the purchase of an analytical system that employs a version of automated Edman degradation to perform high sensitivity protein sequencing analyses. The components of the proposed system are: (1) a model 470A Gas Phase Protein Sequencer from Applied Biosciences, (2) a high performance liquid chromatography apparatus from Waters Associates with an integrator and data processing system from Nelson Analytical. This instrument system will be housed and operated as part of a new shared instrument facility for protein chemistry that is being constructed by the Columbia University College of Physicians and Surgeons. It is anticipated that the Principal Investigator and the other three major users will utilize the sequencer system for 80% of the time initially. Ten other users will require access for the remaining 20% of time. As more personnel are added to this core facility, it is estimated that occasional users will consume a greater proportion of time when the instrument is operating at full potential. The utilization of the sequencer of the sequencer system will be supervised by an Advisory Committee and all faculty members will be eligible to apply for access to its function.